Denver ? Three U.S. soldiers have been charged with involuntary manslaughter in the drowning of an Iraqi detainee who was shoved off a bridge near Baghdad in January, the military said Friday.

A fourth soldier faces charges for allegedly pushing a second Iraqi into the same river, the Tigris, in the city of Samarra. That man survived.

Both Iraqis were civilians who had been detained for a curfew violation, Army spokesman Lt. Col. Jonathan Withington said. He said the four soldiers, all from Fort Carson, were on patrol at the time. All have since returned to the Colorado post.

Sgt. 1st Class Tracy E. Perkins, 33, and 1st Lt. Jack M. Saville, 24, are charged with involuntary manslaughter, assault, conspiracy and obstruction of justice, according to a summary by the Army. Sgt. Reggie Martinez, 24, is charged with involuntary manslaughter and Spc. Terry Bowman, 21, is charged with assault. All are charged with making false statements.

Saville gave the order to push both men in and then persuaded the others to deny that it happened, the military said.